Alex Ferguson has devised a two-pronged strategy to beat Barcelona in tomorrow's Champions League final, including a radical rescue plan should Manchester United fall behind at Wembley.

The Scot has spent the past two weeks training his side in two possible formations; one being a 3-4-3 formation, to use if United find themselves chasing the game. He has also asked winger Nani to mimic Lionel Messi in practice sessions, as he attempts to concoct a plan to contain the World Footballer of the Year.

Since securing a record 19th domestic league title with a 1-1 draw at Blackburn on May 14, Ferguson's first-team squad has focused solely on finding a way to overcome Pep Guardiola's Spanish champions.

Although United faced Blackpool at Old Trafford in the final game of the Premier League season last Sunday, preparations for that fixture were minimal due to the hours spent plotting to beat Barcelona.

Following the 2-0 defeat in Rome two years ago, when Cristiano Ronaldo complained that "the tactics were not good," Ferguson repeatedly insisted that he knew the reason for United's downfall.

The manager, who has never publicly revealed his thoughts on the decisive factor in his team's defeat, admitted last week that Rome has been "analysed many times'' as he and his coaches have moved to ensure that United cannot use lack of preparation as mitigation for defeat.

Ferguson has yet to inform his players of his starting XI for Wembley, but the Scot is understood to have settled on his selection, with Fabio da Silva expected to start at right-back and Michael Carrick holding off a late challenge from Darren Fletcher to play in midfield.

But the tactical blueprint for Wembley is now in place following the detailed training sessions that have included 11-a-side practice games between the first team and squad members lining up as Barcelona.

With Ferguson wary of Barcelona's slick passing game and the goal threat of Messi, Portuguese winger Nani has performed the 'Messi' role in training, replicating the Argentine forward's movement in the final third of the pitch.

Michael Owen has also been asked to play as David Villa, Barcelona's £34m striker who enjoys cutting in from the left flank, while Paul Scholes has performed as the Spanish playmaker Andres Iniesta.

And while United have worked at length on a 4-4-2 formation with Wayne Rooney and Javier Hernandez as the focal point of the attack, a plan is also in place to move to 3-4-3 should Barcelona take a lead and leave United chasing the game.

Chris Smalling, set to be named on the bench on Saturday, has trained as the third man at the back alongside Rio Ferdinand and Nemanja Vidic.

The former Fulham man would likely replace Ji-Sung Park, with Fabio and Patrice Evra advancing into midfield behind a front three of Rooney, Hernandez and Antonio Valencia.

VISIBLY

When losing 2-1 to Arsenal at the Emirates in the Champions League's last 16 in February, Barcelona visibly tired in the final 20 minutes of the game, a factor noted by Ferguson and his back-room team.

Guardiola's comparative lack of rotation of players has also led to suspicions that Barcelona's key players will arrive at Wembley and perform on a traditionally taxing pitch having endured a more physically demanding season than many of their rivals.

Barcelona remain favourites, but Ferguson insists that United will not be fazed by facing a team billed as one of the greatest club sides of all-time.